Ask HN: Where should I begin learning low-level computing, asm?

I'm not in any way interested in trying to become a professional software engineer (though that outcome wouldn't isn't objectionable), I just want to learn how a computer functions from its lowest levels to however high it can go, in that linear order. So I'd like to explore computer processing mechanics (just <i>what</i> is a processor doing and with what?) and assembly with that (near direct manipulation of memory and processor), followed by C, and so on.<p>Would the esteemed community at HN be willing to provide some direction and starting points for such a project? Comments even? I imagine the project trajectory may need to adjust to certain realities of computing. Thanks ahead of time.